Principal Investigator/Program Director (Last, first, middle): Stallcup, Michael, Robert RESEARCH &RELATED Other Project Information 1. * Are Human Subjects Involved? m Yes l No 1.a. If YES to Human Subjects Is the IRB review Pending? m Yes m No IRB Approval Date: Exemption Number: 1 2 3 4 5 6 Human Subject Assurance Number 2. * Are Vertebrate Animals Used? m Yes l No 2.a. If YES to Vertebrate Animals Is the IACUC review Pending? m Yes m No IACUC Approval Date: Animal Welfare Assurance Number 3. * Is proprietary/privileged information m Yes l No included in the application? 4.a.* Does this project have an actual or potential impact on m Yes l No the environment? 4.b. If yes, please explain: 4.c. If this project has an actual or potential impact on the environment, has an exemption been authorized or an environmental assessment (EA) or environmental impact statement (EIS) been performed? m Yes m No 4.d. If yes, please explain: 5.a.* Does this project involve activities outside the U.S. or m Yes l No partnership with International Collaborators? 5.b. If yes, identify countries: 5.c. Optional Explanation: 6. * Project Summary/Abstract 7762-PROJECT_SUMMARY.pdf Mime Type: application/pdf 7. * Project Narrative 5806-PROJECT_NARRATIVE.pdf Mime Type: application/pdf 8. Bibliography &References Cited 9321-BIBLIOGRAPHY_AND_REFERENMCEimSe_CTyITpEeD: a.pdpflication/pdf 9. Facilities &Other Resources 9312-FACILITIES_AND_OTHER_RESOMURimCeETSy.pdef: application/pdf 10. Equipment 1550-EQUIPMENT.pdf Mime Type: application/pdf Tracking Number: Other Information Page 5 OMB Number: 4040-0001 Expiration Date: 04/30/2008 Principal Investigator/Program Director (Last, first, middle): Stallcup, Michael, Robert PROJECT SUMMARY Nuclear receptors (NRs) and other DNA-binding transcription factors regulate transcription of their target genes by recruiting coregulator proteins to the promoter of the target genes. Many coregulators can assist NRs as either coactivators or corepressors, depending on the regulatory context of the promoter. However, the mechanisms that govern whether a specific coregulator functions as coactivator or corepressor is unknown and will be a central focus of this application. Transcriptional repression involves recruitment of corepressor complexes which often include enzymes that deacetylate and make repressive methylation marks on histones. In particular, di- and trimethylation of lysine 9 of histone H3 (H3 K9) in gene promoters has been associated with gene repression. Knock-out mouse studies of the euchromatin-associated H3 K9 methyltransferases G9a and GLP indicated that these two enzymes are responsible for the majority of mono- and dimethylation of H3 K9 in cells. The knock-out mouse results plus additional biochemical studies indicate that G9a and GLP function as heterodimer partners for at least some of their functions. G9a is also associated with corepressor complexes that mediate the effects of several repressive transcription factors. G9a and GLP can also function as coactivators for NRs, suggesting that G9a may play a critical role as a regulatory switch between activation and repression of transcription, depending on the regulatory context on a particular promoter. The goal of this project is to understand the mechanisms of coactivator and corepressor function by G9a and GLP. The central hypothesis is that specific protein- protein interactions determine whether G9a and GLP function as coactivators or corepressors on a given promoter. Among other protein-protein interactions, the ability of G9a and GLP to bind preferentially to histone H3 that is dimethylated at lysine 9 (recently discovered in this laboratory) will be investigated for its role in coregulator function. In addition, common, distinct, and complementary aspects of G9a and GLP function will be defined. Toward that end, the domains and specific protein- protein interactions of the domains of G9a and GLP which are important for their functions as coactivators and corepressors will be determined. Analyses will be performed on both transiently transfected reporter genes and endogenous target genes of G9a and GLP. These studies will thus significantly extend our understanding of the specific contributions of coregulators and histone modifications to transcriptional regulation of genes. In addition, since NRs play many critical roles in normal and pathological regulation of endocrine and metabolic physiology, the proposed studies will provide new knowledge that has important implications for human health. Project Description Page 6